Method and apparatus for securing electrical connectors

ABSTRACT

Methods and apparatus for securing a first electrical connector mounted to an electronic module to a second electrical connector supported by a support structure, such that the first and second electrical connectors mate in an electrically conductive manner. The support structure can be an electrical board supported by a chassis. The apparatus includes a latch having a first end configured to engage the chassis and a lever portion configured to exert a force on the electronic module when in a first position. This force allows the first electrical connector to be urged towards the second electrical connector. The apparatus also has a compliant member configured to bias the lever portion away from the first position, and a catch configured to secure the latch in the first position. 
     In the method, a first force is applied to the electronic module to urge the electronic module towards the board from a first position to a second position to thereby cause the first electrical connector to mate in an electrically conductive manner with the second electrical connector. Thereafter a second force is applied to the electronic module to maintain the electronic module in the second position. The second force is selected to be not greater than a predetermined force.

FIELD OF THE INVENTION

This invention pertains to methods and apparatus for securely engaging amodule, such as a computer component, into a connector which issupported on a chassis or a main board.

BACKGROUND OF THE INVENTION

The present invention is particularly useful in systems such as diskarrays and the like, but can be applied to any situation where it isdesired to securely mount a component or module into a connector whichis supported on or by a chassis or frame or the like. A disk array is abattery of computer memory disk drives which are mounted together withina cabinet. Disk arrays fit within a category of computer equipment knownas “storage systems” because the system is used to store large amount ofdata. A typical use of a disk array is an Internet server which storesweb site information, including content which can be accessed from theweb site. It is not uncommon for a disk array to have the capacity tostore several terabytes of data (a terabyte being 1000 gigabytes).

A disk array typically consists of a cabinet which houses a plurality ofdisk drives. The disk drives are mounted by connectors to a board or“plane”, which is supported by a chassis, all within the cabinet of thedisk array. Depending on the location of the plane within the cabinet,the plane can be known as a “midplane” (mounted towards the middle ofthe cabinet so that disk drives can be mounted to either side of theplane), or a “back plane” (mounted towards the back of the cabinet sothat the disk drives are only mounted to one side of the plane). Thechassis can further include framework for supporting the disk drives,and to facilitate orienting the disk drive to the connectors. In thismanner a disk drive can be inserted or removed from the array.

The plane further supports electrical conductors for routing power anddata to and from the disk drives via the connectors. The electricalconductors are routed to a main connection, allowing a remote computerto store and retrieve data from the disk array. The connectors on theplane can be female connectors which are configured to receive maleconnector pins on the disk drive. Each disk drive typically has aplurality of such “pins” which mate with the corresponding femaleconnectors on the plane to allow the individual disk drives to send andreceive data via the electrical conductors. In other systems, the modulecan have female connectors, and the panel or board to which the moduleis being mounted can have corresponding male pins for completing theconnection. Although we use the term “pin” to describe the malecomponent of the connector assembly, it is understood that the “pin” canin fact be a blade, a cylinder, a rectangle, or any other protrudinggeometry which allows it to be inserted into a female receivingconnector component.

Turning briefly to FIG. 1A, a side view of a prior art connector 1 isshown in cross section. The connector 1 is mounted on the plane 2. Theconnector housing 1 a defines a cavity 3, in which is located femaleconnectors 4 and 5, which together form a single female connectorcomponent. Female connectors 4 and 5 are spring biased towards thecenter of the cavity 3 such that when a male connector pin 6, which isconnected to module 7, is moved in direction “A”, the female connectorsare pushed apart, but remain biased against the pin 6. Such biasingassures good electrical contact between the connector components.

To maintain the module securely seated in its receptacle within theframe of the disk array, a latch can be provided which secures themodule to the chassis or frame. With reference to FIG. 2, a prior artdisk array 10 is shown. The disk array comprises a cabinet 11 in which achassis or frame 12 is disposed. The chassis 12 comprises side rails 23,a top rail 22, and intermediate vertical rails 15 and 17, which whenassembled form openings 13 in which a disk drive, such as disk drive 14,can be inserted. The disk drives mate to connectors 1 which are mountedto a plane 25, visible through the openings formed by the chassismembers. Disk drive 14 is secured within the opening 13, and is securelyseated to connector 1, via the latch 20. Turning now to FIG. 3, a leftside sectional view of the upper left opening 13 of the prior art diskarray 10 of FIG. 2 is shown. As can be seen, intermediate chassis rail15 has an anchor point 21 which is configured to be engaged by the latch20 of FIG. 2.

Turning now to FIG. 4, a perspective view of the disk drive 14 of FIG. 2is shown in more detail. FIG. 4 depicts the prior art latch 20 and itsmethod of engagement with intermediate chassis rail 15. To secure thedisk drive 14 to the midplane (25 of FIG. 3), the far end 29 of thelatch 20 is moved in the direction of arrow “B” until handle catchportion 31 engages the disk catch portion 32 to maintain the latch 20 inthe secured position. The latch assembly is shown in top view in FIG. 5.The latch 20 of FIG. 5 includes a leveraging edge 30 which engagesflange 33, which acts as an anchor point for the latch. As can be seen,when latch 20 engages anchor point 33 and is moved in direction “B”, thelatch 20 pivots about pivot point 28 and the disk drive 14 is pulled indirection “A” into the opening 13. Latch 20 is moved in direction “B”until the latch is secured by the catch 32. Catch 32 can comprise aspring-release catch having moveable part 34 which moves in direction“C” to allow catch pin 31 on latch 20 to move past the catch pin. Thelatch is secured in the “locked” position when the catch pin moves backto its biased position. By pulling the latch in the direction oppositeto “B” the catch pin is pushed aside, allowing the disk drive to befreed from the anchor point 33.

In designing a connector system for an electronic module, two primaryconsiderations are taken into account. The first is to ensure that theconnector pin (6 of FIG. 1A) is sufficiently engaged by the connectorcontacts 4 and 5. This is necessary for the obvious reason that if nocontact is made, data and power cannot be transferred to and from thedisk drive. The second consideration is to ensure that excessive forceis not applied to the connector system when the connection is made andthe module is seated. This is necessary since a force exerted on themidplane can lead to premature failure of the midplane, failure ofsolder connections, and damage to the connector components. Further,forces exerted on components within the module by the module connectorscan lead to failure of these components as well. As shown in FIG. 1A,the first objective of ensuring a connection between the contacts isachieved by designing the connector pins 6 and the contacts 4 and 5 suchthat there is a reserve wipe distance, d_(rw), i.e., a distance overwhich the pin 6 travels after it has made initial contact with theconnector contacts 4 and 5. The second objective of avoiding anexcessive force on the midplane is achieved by designing the connectorassembly such that there is a design gap, d_(dg), between the connectorhousing 1 a and the disk drive connector housing 7.

However, in production units the actual wipe distance and the actual gapdistance can vary from the design wipe distance and the design gapdistance. This variance is due to tolerances in the various componentsin the chassis, the plane and the module. These tolerances can be due tosheet metal tolerances, printed circuit board (e.g., midplane)tolerances, press-in standoff tolerances, and connector tolerances, toname just a few. The cumulative effect of these tolerances is expressedby the equation

tol _(sys)=(tol ₁ ² +tol ₂ ² +tol ₃ ² + . . . +tol _(n) ²)^(½),

where tol_(sys) is the cumulative tolerance of the system, and tol_(1−n)represent the various tolerances of the components. If the systemtolerance indicates that the actual gap distance might be reduced tozero, then the situation shown in FIG. 1B can occur, wherein the moduleconnector housing 7 butts up against the connector housing 1 a. In thisinstance an undesirable force can be applied to the midplane 2 by aforce in the direction “A” exerted by the latch (20 of FIGS. 2 and 4).Likewise, if the system tolerance indicates that the actual wipedistance might be reduced to zero or less, then the pin 6 of FIG. 1A canfail to mate with the connectors 4 and 5, which is obviouslyundesirable.

One solution to overcome the problem of cumulative tolerances is toreduce the various tolerances which contribute to the overall systemtolerance. However, this is not always practical due to machining andfabrication limitations, and can be difficult to implement sincecomponents of the system can be manufactured by a variety of differentmanufacturers. Another solution is to increase the length of theconnector pin 6. This will insure that a wipe distance is alwaysachieved while allowing room for a design gap to be maintained. However,this is not practical for two reasons. First, an overly long connectorpin can contact the midplane, exerting an undesirable force on themidplane and possibly allowing the connector pin to bend and damage thecontacts 4 and 5. Second, the dimensions of many connector componentsare established by industry standards. These standards are typically acompromise to achieve the best solution to a variety of designconsiderations. Changing these standards can be a long and arduousprocess, and can exacerbate the other problems that are addressed by thestandard. Further, changing an industry standard will result inincompatible units being present in the field (old standard equipmentand new standard equipment), and the cost to change production lines tomeet the new standard can be considerable.

What is needed then is a method and apparatus for allowing an electronicmodule to be securely seated in a connector, such that electricalcontact between the connector components is achieved and maintained,while avoiding excessive forces on the connector components and theirassociated circuit boards.

SUMMARY OF THE INVENTION

The invention includes methods and apparatus for securing a firstelectrical connector mounted to an electronic module to a secondelectrical connector supported by a support structure. The supportstructure can comprise an electrical board supported by a chassis. Theinvention facilitates mating of the first and second electricalconnectors in an electrically conductive manner, while at the same timehelping to reduce undue stress on the connector components.

One embodiment of the apparatus includes a latch with a first endconfigured to engage the support structure, and a lever portionconfigured to exert a force on the electronic module when the leverportion is in a first “locked” position. This force allows theelectrical connector on the module to be urged towards the electricalconnector on the electrical board, and mate therewith. The apparatusalso has a compliant member configured to bias the lever portion awayfrom the first “locked” position, and a catch configured to secure thelatch in the locked position. In this manner, the compliant memberapplies a biasing force to the latch, which force is transmitted to themodule. The biasing force has the effect of reducing the force appliedto the connectors by the latch, thereby reducing the risk ofoverstressing of the connector components.

In one embodiment of the apparatus, the compliant member can comprise aspring disposed between the support structure and the first end of thelatch which engages the support structure. In another embodiment thecompliant member can be integral with the latch, such that the compliantmember comprises a segment of the lever portion of the latch. In thisembodiment, the segment of the lever portion of the latch can befabricated from a resilient material configured to orient the leverportion in a normal position when the lever portion of the latch isunstressed. When the lever portion is moved from the normal position tothe first or “locked” position, the resilient segment of the leverportion is stressed to bias the lever portion away from the lockedposition and towards the normal position. This has the effect ofapplying the biasing force to the connectors, as described above.

In one embodiment of a method in accordance with the present invention afirst force is applied to the electronic module to urge the electronicmodule towards the support structure from a first position to a secondposition, to thereby cause the first electrical connector on the moduleto mate in an electrically conductive manner with the second electricalconnector on the support structure. Thereafter a second force is appliedto the electronic module to maintain the electronic module in thesecond, mated, position. The second force is selected to be not greaterthan a predetermined force, and is preferably selected to be a forcewhich will not cause damage to the first connector, the secondconnector, or the board. The second force can be produced by applying abiasing force to the module using apparatus in accordance with thepresent invention. The method can further include providing a compliantmember configured to exert the second force on the electronic modulewhen the compliant member is reconfigured from a normal position to abiased position. Further, the method can include providing a catch tohold the compliant member in the second position.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a sectional side elevation view of a prior art module andmidplane connector assembly.

FIG. 1B is a sectional side elevation view of the prior art connectorassembly of FIG. 1A showing a zero-gap situation between the module andthe midplane connector.

FIG. 2 is a front elevation view of a prior art disk array.

FIG. 3 is a left side sectional detail of the upper left corner of theprior art disk array shown in FIG. 3, showing the housing formed toreceive a disk drive.

FIG. 4 is a close up perspective of a prior art disk drive mounted inthe prior art disk array shown in FIG. 2.

FIG. 5 is a plan view of the prior art module latch shown in FIG. 4.

FIG. 6A is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with one embodiment of thepresent invention.

FIG. 6B is a force balance diagram showing how the apparatus depicted inFIG. 6A exerts a biasing force.

FIG. 7 is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with a second embodiment ofthe present showing the latch in the unlocked position.

FIG. 8 is a plan view of the compliant latch shown in FIG. 7, showingthe latch in the locked position.

FIG. 9 is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with a third embodiment ofthe present invention.

FIG. 10 is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with a fourth embodiment ofthe present invention.

FIG. 11 is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with a fifth embodiment ofthe present invention.

FIG. 12 is a plan view of a compliant latch for securing a moduleconnector to a board connector in accordance with a variation on thesecond embodiment of the present invention shown in FIGS. 7 and 8.

FIG. 13 is a sectional view of the compliant latch shown in FIG. 12.

FIG. 14 is a front elevation view of an upper left corner of a diskarray containing a compliant latch for securing a module into a board inaccordance with a sixth embodiment of the present invention.

FIG. 15A is a plan view of an seventh embodiment of the presentinvention using a compliant member to secure a module connector to aboard connector.

FIG. 15B is a detail of a corner of the disk drive and the compliantmember of FIG. 15A.

FIG. 15C is a force balance diagram showing how the apparatus depictedin FIG. 15A exerts a biasing force.

DETAILED DESCRIPTION OF THE INVENTION

The invention includes methods and apparatus for securing a firstelectrical connector mounted to an electronic module to a secondelectrical connector supported by a support structure, such that thefirst and second electrical connectors mate in an electricallyconductive manner without undue stress being applied to the connectors.The support structure can for example be an electrical board supportedby a chassis. The methods and apparatus facilitate in keeping theelectrical connectors engaged, while also reducing the force on theconnectors so that undue force is not applied to the connectors, or tothe electrical board via the connectors. The objectives of the inventionare achieved by providing a compliant member which acts to buffer theforce applied to the electronic module in securing the module connectorto the board connector. In essence, the compliant member applies thesustained connector mating force to the electronic module. Excessiveforces experienced by the electrical connectors can thus be transferredto the compliant member, causing the compliant member to deform and thusrelieve the force on the electrical connectors.

Accordingly, an apparatus in accordance with the present invention caninclude a compliant member configured to be deformed from a first normalposition to a second stressed position. The compliant member has a firstportion configured to exert a force on the chassis, and a second portionconfigured to exert a force on the electronic module when the compliantmember is in the stressed position. This force causes the electricalconnector on the electronic module to be biased away from the electricalconnector mounted on the board. To prevent the electrical connectorsfrom parting, a catch is provided to secure the electronic module in theposition established when the compliant member is in the stressedposition.

Likewise, a method in accordance with the present invention comprisesapplying a first force to the electronic module to urge the electronicmodule towards the support structure from a first position to a secondposition, to thereby cause the electrical connectors to mate.Thereafter, a second force is applied to the electronic module tomaintain the electronic module in the second position where theconnectors are mated. The second force is selected to be not greaterthan a predetermined force which will not cause damage to the firstconnector, the second connector, or the support structure, and inparticular the electrical board.

Although in the following discussion the invention will be described inthe setting of securing a disk drive in a disk array, it is understoodthat the invention is applicable to any situation where it is desirableto secure an electronic module to a support structure. The supportstructure can comprise a single structure, or a combined structure, suchas an electrical board supported on a chassis. Accordingly, the term“electronic module” or “module” should be broadly interpreted, and caninclude for example, and without limitation, items such as a disk drive,a circuit board, a circuit component, a power supply, and a cableconnection (such as a parallel or serial port cable connected to apersonal computer). A “circuit board” can include, by way of exampleonly, a printed circuit board (“PCB”) containing computer memory chips,a modem, an embedded web server, and a video display card. The commonaspect of all of these “modules” is that they have an electricalconnector which is configured to mate with another electrical connector.The examples which follow all discuss securing a disk drive in a diskarray, but it is understood that the expression “disk drive” can bereplaced with the more general term “electronic module”.

Likewise, when we describe the module being mounted to an electricalconnector supported on an electrical board or a plane, the descriptionshould not be considered as limiting. While the description below willbe directed towards a disk array having a “plane” to which a pluralityof disk drives can be mounted, the invention is not limited to thisapplication. Accordingly, when we say that the module is mounted to an“electrical board”, “board”, or “plane”, we mean that the electricalconnector of the module is engaged with a second, compatible electricalconnector, and which is typically supported by a surface. An “electricalboard” can include a plane (midplane, backplane, etc.) in a disk array,as well as a printed circuit board, or connectors mounted to a frame.The common feature is that the connector to which the module connectoris intended to mate is mounted on a supporting structure, and thestructure conveys electrical conductors to the electrical connector.

Although the description below is directed towards electrical connectorswhich connect in the manner shown in FIG. 1A, the invention should notbe considered as limited to such. For example, the connection of the twoconnectors can comprise a soldered connection, rather than the “push-in”type of connection shown. The concerns described above regardingavoiding excessive force on connectors are equally applicable tosoldered connections as they are to push-in connections.

Accordingly, notwithstanding the environment in which the invention isset forth below, the invention should be considered broadly, within thescope of the above definitions, as applying to any electronic modulewhich has a first connector part which mates with a second connectorpart, the second connector part being mounted to an electrical board.

The Apparatus

Turning now to FIG. 6A, a first embodiment of an apparatus in accordancewith the present invention is shown. FIG. 6A depicts a plan view of anelectronic module, shown here as a disk drive 14, which is mounted in adisk array (similar to 10 of FIG. 2). This disk drive 14 has a firstelectrical connector 7 which is configured to mate with the disk arrayelectrical connector 1. The disk array electrical connector 1 is mountedto an electrical board (a “plane”) 25, which conveys electricalconductors providing power and electrical signals to the disk drive 14.The plane is supported by a chassis, which comprises side rail 23 andintermediate rail 15. The disk drive 14 is mounted in the disk array byurging it in direction “A” using a first force until the connectors 7and 1 mate. Once the disk drive is mounted to the board and theelectrical connectors are engaged, the disk drive is secured in placeusing the latch 40. Latch 40 is configured to be pivotally mounted tothe disk drive 14 at pivot point 28, to thereby allow the latch 40 tomove in direction “J” or “J′”. On one side of the pivot point 28 is alatch handle or lever portion 44 which is moved in direction “E” to theposition shown to urge the disk drive connector 7 into the planeconnector 1. On the other side of the pivot point 28 the latch 40 has afirst end 45 which is configured to engage the chassis at chassis flange51. However, this engagement is indirect. That is, the first end 45 ofthe latch does not directly engage the chassis flange 51, but does soindirectly. This indirect engagement is accomplished via a compliantmember 46 which is disposed between the first end 45 of the latch andthe chassis flange 51.

As shown, the compliant member 46 comprises a spring positioned to exertequal and opposite forces on the first end 45 of the latch and thechassis flange 51. When the latch 40 is placed in the position shown inFIG. 6A to secure the disk drive 14 to the plane 25, the spring 46 iscompressed between the first end 45 of the latch and the flange 51. Thespring thus exerts a clockwise moment on the latch 40, biasing the latchhandle or lever portion 44 in direction “D”. The latch 40, andconsequently the disk drive 14, is held in place against this biasingforce by catch 42, which is securely affixed to the disk drive. Bybiasing the latch handle in direction “D”, forces which can existbetween the disk drive connector 7 and the plane connector 1 are therebyreduced. This is apparent from a simple static force diagram, as shownin FIG. 6B, in which the biasing force F_(B) imparted to the latch lever44 by the compliant member 46 reduces the compressive force F_(C)between the connector parts 7 and 1. As a result, the resultant forceexerted on the connectors 1 and 7 is reduced, yet the disk drive 14 isstill held in secure position within the disk array, and a sufficientforce is still applied between the connectors 7 and 1 to maintain theconnectors in electrical contact.

Although the compliant member is shown in FIG. 6A as a metal coilspring, it is understood that it can be any kind of spring. Moregenerally, the compliant member can comprise any device which can bedeformed from a first “normal” unstressed (or “at-rest”) position to asecond, stressed position. By way of example only, the compliant membercan be a metal spring, a plastic or polymeric spring, or a resilientmaterial such as rubber or the like. Further, the compliant member cancomprise a chamber having a closed hollow center filled with acompressible fluid, such as air. The common criteria for the possiblechoices for the compliant member is that after being deformed from thenormal, unstressed position, the compliant member exerts a restorativeforce to attempt to return to the normal position. It is thisrestorative force which is used to bias the disk drive 14 away from theelectrical board 25, but which is resisted as a result of the catch 42in FIG. 6A.

A second embodiment of an apparatus in accordance with the presentinvention is shown in FIGS. 7 and 8. FIG. 7 depicts a top plan view ofthe apparatus in a partially closed position, and FIG. 8 shows theapparatus shown in FIG. 7, but in the fully “locked” position. For thesake of simplicity, the electrical board and the electrical connectorsare not shown in FIGS. 7 and 8, but they can be identical to the board25 and the connectors 1 and 7 shown in FIG. 6A. With reference to FIG.7, the apparatus comprises a latch 80 which is configured to bepivotally mounted to a disk drive 14 at a pivot point 81, allowing thelatch to rotate in a clockwise and counter-clockwise direction in theview shown. The latch 80 has a first end 83 disposed on a first side ofthe pivot point 81. The first end 83 is configured to engage the flange51 of chassis member 15. The latch further comprises a lever portion 82which is disposed on the other side of the pivot point 81 from the latchfirst end 83. The lever portion of the latch comprises a segment 87which acts as the compliant member. In the example shown in FIG. 7, thecompliant segment of the latch lever has slots or “kerfs” 84 which arecut into the handle or lever portion 82 of the latch. When the segment87 is fabricated from a resilient material, such as plastic, then thekerfs allow the lever portion to be bent in a downward direction, asindicated in FIG. 8.

In operation, the lever portion 82 of latch 80 is pushed in thedirection “B”. In so doing, the first end 83 of the latch engages thechassis flange 51. Since the latch 80 is mounted to the disk drive 14 atthe pivot point 81, the engagement of the first end 83 with the flange51 causes the disk drive to be urged in direction “B”, causing theconnectors (1 and 7 of FIG. 6A) to mate. As force is applied to thelever portion 82 of the latch 80, the flexible segment 87 bends,allowing the lever portion to move in a direction indicated by arrow“B”. A catch 88, which can comprise a piece of spring steel rigidlyaffixed to the disk drive, moves in direction “D” to allow the tip 87 ofthe latch 80 to continue moving in direction “B”. Once the tip 87 of thelatch 80 has passed the bend 89 in the catch 88, the catch moves back indirection “E”, as shown in FIG. 8, to secure the lever portion 82 of thelatch 80 in the position shown. In this position, the compliant segment87 of the latch 80 is biased in direction “G”, thereby exerting abiasing force on the disk drive 14 via the catch 88. This biasing forcereduces the risk of overstressing the connector components 1 and 7 (FIG.6A). However, the disk drive 14 is held in place by virtue of the catch88, such that the electrical connectors remain electrically matednotwithstanding the biasing force.

A variation of the latch 80 of FIGS. 7 and 8 is shown in FIGS. 12 and13. FIG. 12 depicts a top view of a latch 160 which can be used in thepresent invention. The latch 160 has a first end 162 for engaging achassis flange, such as 51 of FIG. 7, and a mounting point 81, allowingthe latch 160 to be mounted to a disk drive in a manner similar to thatshown in FIG. 7. The latch 160 further comprises a lever portion 164,which acts as the compliant member. A cross section of the lever portion164 is depicted in FIG. 13. As shown, the lever portion is constructedin the shape of a cantilevered beam, having outer flanges 165, and acentral web 167. The lever portion 164 of the latch 160 is preferablyconstructed from a resilient material, such as plastic, and morepreferably has a known modulus of elasticity. Accordingly, the leverportion 164 can be designed such that a known bending angle of the leverportion produces a known moment at the outer end 168 (FIG. 12) of thelever portion when the lever portion is deflected in direction “B” fromthe normal position shown in FIG. 12. This moment produces the biasingforce which is exerted on a catch (such as catch 88 of FIG. 7), which istransmitted to a disk drive to which the latch 160 can be affixed. Asdescribed above, the biasing force reduces the risk of the electricalconnectors (1 and 7 of FIG. 6A) being overstressed.

It is understood that the cross-section of the lever portion 164 of thecompliant latch 160 depicted in FIG. 13 is but one form of acantilevered beam section which can be used in this embodiment. Otherknown beam cross sections, such as an “I-beam” section, can also beused. If the modulus of elasticity of the material of construction ofthe lever portion 164 is known, then once a particular cross-sectionalgeometry is selected, for a given angular displacement of the leverportion the compliant force can be calculated using known formulae.

With reference to FIG. 9, a third embodiment of an apparatus inaccordance with the present invention is shown. FIG. 9 depicts a topplan view of the apparatus in a fully closed or “locked” position. Forthe sake of simplicity, the electrical board and the electricalconnectors are not shown in FIG. 9, but they can be identical to theboard 25 and the connectors 1 and 7 shown in FIG. 6A. With reference toFIG. 9, the apparatus comprises a latch 100 which is configured to bepivotally mounted to a disk drive 14 at pivot point 108, allowing thelatch to rotate in a clockwise and counterclockwise direction in theview shown. The latch further comprises a compliant member 102, whichcan be disposed within a hollow chamber (not shown) formed within thelatch 100. The compliant member 102 can be held in place in the hollowchamber at a first end 103 of the member by pins 106 and 107, whichextend inwardly into the chamber. By way of example only, the compliantmember can comprise a flat spring, such as a spring made from a piece offlat spring steel, or a resilient plastic material. The compliant member102 can also be made from a piece of metal spring wire. The compliantmember has a second end 104 which is disposed on one side of the pivotpoint 108, and which acts as the first end of the latch 100 for purposesof engaging the flange 51 of chassis member 15. Disposed on the otherside of the pivot point from the compliant member second end 104 is thelatch lever portion 110. The outer end of the lever portion 110 isprovided with a tongue 112 which allows the latch to be secured in theposition shown by catch 32. Catch 32 can operate in the same manner asthe prior art catch 32, shown in FIG. 5 and described above.

When latch 100 of FIG. 9 is moved to the “locked” position, as shown inthe figure, the second end 104 of the complaint member 102 engages thechassis flange 15, causing the disk drive 14 to be urged in direction“A” by virtue of the forces exerted on the disk drive by the latch 100at the pivot point 108. The disk drive consequently moves in direction“A” until the connectors (1 and 7 of FIG. 6A) are electrically mated.When the disk drive is seated and the latch 100 is in the “locked”position shown, the first end 103 of the compliant member 102 isdeflected in the direction indicated by arrow “E” from a normal positionto a stressed position. The outer end of the latch lever portion 110 isthen held in position by catch 32. As a result of this deflection of thecompliant member, a biasing force is exerted on the catch pin 34 in thedirection “D”. Since the catch 32 is securely mounted to the disk drive14, the biasing force is thereby imparted to the disk drive, therebyreducing the force exerted on the connectors 1 and 7. Thus, the biasingforce reduces the risk of overstressing the connector components 1 and 7(FIG. 6A), while still allowing the disk drive 14 to be held in place byvirtue of the catch 32, such that the electrical connectors remainelectrically mated.

In FIG. 10 a fourth embodiment of an apparatus in accordance with thepresent invention is shown. FIG. 10 depicts a top plan view of theapparatus in an “unlocked” position. For the sake of simplicity, theelectrical board and the electrical connectors are not shown in FIG. 10,but they can be identical to the board 25 and the connectors 1 and 7shown in FIG. 6A. With reference to FIG. 10, the apparatus comprises alatch 120 which defines a mounting slot 124. The mounting slot isconfigured to receive a mounting pin 126 which is affixed to the diskdrive 14. The slot is disposed within a receiving chamber 128 in thelatch 120. The receiving chamber 128 is configured to receive acompliant member 130, such that the compliant member 130 is held inposition between a closed end 129 of the receiving chamber 128 and themounting pin 126. In this manner, the latch 120 is free to move withinthe slot in the direction indicated by arrow “H”, as well as pivot in aclockwise or counterclockwise direction in the view shown. Although thecompliant member 130 is shown as a coiled spring, it is understood thatthe compliant member can comprise any compressible, resilient componentwhich can fit within the chamber 128 and be compressed between thechamber upper end 129 and the mounting pin 126, to thereby exert abiasing force on the latch 120.

The latch 120 further comprises a first end 127 which is disposed on oneside of the slot 124. The latch first end 127 is configured to engagethe flange 51 of the chassis member 15, such that the disk drive 14 canbe urged forward in direction “A” by the latch 120. The latch alsoincludes a lever portion 123 which is disposed on the opposite side ofthe slot 124 as the first end 127. The outer end of the lever portion123 of the latch 120 can comprise a tongue 125 and groove 131 which areconfigured to receive a securing pin 34 of a catch 32, which is mountedto the disk drive 14. The method of operation of the catch 32 has beendescribed above, and will not be further described with respect to FIG.10.

In operation, when the lever portion of the latch is moved in direction“B”, the first end 127 of the latch engages the flange 51 of the chassismember 15. The force applied to the first end 127 of the latch by theflange 51 is imparted to the compliant member 130 by the upper end 129of the chamber 128. This causes the compliant member to compress,exerting a force on the mounting pin 126, which force urges the diskdrive 14 in the direction “A” until the electrical connectors (notshown) have electrically mated and are seated. The latch lever portion123 continues to move in direction “B” until the groove 131 in the outerend of the latch 120 is engaged by catch pin 34 in a manner similar tothat shown in FIG. 9. Thereafter, the moving force is removed from thelatch lever portion 123, and the latch 120 remains in the secured orlocked position. In the locked position, the compliant member 130 exertsa biasing force on the latch 120, resulting in a force on the catch pin34 in the direction shown by arrow “D”, which is imparted to the diskdrive 14 and the electrical connector 7 (FIG. 6A). As described above,this resulting force reduces the risk of overstressing the connectorcomponents 1 and 7 (FIG. 6A), while still allowing the disk drive 14 tobe held in place by virtue of the catch 32, such that the electricalconnectors remain electrically mated.

Turning now to FIG. 11, a fifth embodiment of an apparatus in accordancewith the present invention is shown. FIG. 11 depicts a top plan view ofthe apparatus in a secured or “locked” position. For the sake ofsimplicity, the electrical board and the electrical connectors are notshown in FIG. 11, but they can be identical to the board 25 and theconnectors 1 and 7 shown in FIG. 6A. With reference to FIG. 11, theapparatus comprises a latch 140 which is configured to be pivotallymounted to a disk drive 14 at pivot point 81, allowing the latch torotate in a clockwise and counterclockwise direction in the view shown.The latch comprises a first end 143 disposed on a first side of thepivot point 81. The first end 143 is configured to engage the flange 51of chassis member 15 when the latch is moved in direction “B”, tothereby urge the disk drive in direction “A”. The latch furthercomprises a lever portion 148 which is disposed on the other side of thepivot point 81 as the latch first end 143. The latch 140 is furtherprovided with a locking handle 144, which is pivotally mounted to thelatch 140 at handle pivot 145. Disposed between the locking handle 144and the lever portion 148 of the latch is a compliant member 150 whichis held in place by an inner surface 152 of the locking handle. Althoughthe compliant member 150 is shown as a coiled spring, it is understoodthat the compliant member can comprise any compressible, resilientcomponent which can fit between the locking handle inner surface 152 andthe lever portion 148 of the latch, and can be compressed therebetweento thereby exert a biasing force on the latch 140. The latch lockinghandle 144, and consequently the latch 140, can be held in a “locked”position (as shown) by catch 146, which is securely affixed to the diskdrive 14.

In operation, the locking handle 144 is moved in the direction shown byarrow “K”, which causes the compliant member 150 to begin to compressand exert a force on the lever portion 148 of the latch 140. This forcecauses the latch to rotate counterclockwise about the pivot point 81until the latch first end 143 engages the chassis flange 51. When thelatch first end is thus engaged with the flange 51, the locking handleexerts a force on the latch 140 at the handle pivot point 145, whichforce is transferred to the disk drive 14 at the latch pivot point 81.This force urges the disk drive 14 in direction “A”, causing theelectrical connectors (not shown) to mate. Locking handle 144 continuesto move in direction “K” until it is engaged in a “locked” position (asshown) by catch 146. At this point, movement of the locking handle isceased. In this “locked” position, the compliant member 150 exerts abiasing force against the inner surface 152 of the locking handle. Thisbiasing force is consequently transmitted to the catch 146, and thus tothe disk drive 14 and the electrical connector 7 (FIG. 6A). As describedabove, this biasing force reduces the risk of overstressing theconnector components 1 and 7 (FIG. 6A), while still allowing the diskdrive 14 to be held in place by virtue of the catch 146, such that theelectrical connectors remain electrically mated.

As can be seen by the various embodiments shown in FIGS. 6 through 13,the compliant member does not need to be a separate component, but cancomprise an integral part of the latch, as depicted in FIGS. 7 and 12.Likewise, the first end of the latch can be formed integrally with thelever portion of the latch as shown in FIGS. 6, 7, 10 and 11, or it cancomprise a portion of the compliant member as shown in FIG. 9.

With reference now to FIG. 14, an alternate, sixth embodiment of anapparatus in accordance with the present invention is shown. FIG. 14depicts a front elevation view of a disk drive 14 mounted in a diskarray, similar to that shown in the prior art depicted in FIG. 2. Thedisk drive 14 is enclosed by a chassis side member 12 on the left,chassis top and bottom members 22 and 16, respectively, and chassisintermediate member 15. It is understood that the disk drive mates to anelectrical plane in a manner similar to that shown in the prior artviews Figs, 1A and 1B, and in FIG. 6A. Unlike the embodiments of theinvention depicted in FIGS. 6 through 11 wherein the latch is pivotallymounted to the disk drive, in the embodiment shown in FIG. 14, theapparatus comprises a latch 180 which is pivotally mounted to thechassis. Accordingly, the latch 180 of FIG. 14 comprises a hinge 182which acts like a door hinge, to allow the latch 180 to swing “outward”from the position shown in FIG. 14 so that the disk drive 14 can beremoved. The latch 180 includes a body portion 186, which acts as thelever portion of the latch to secure the disk drive into the chassis.Disposed between the latch body 186 and the front of the disk drive 14is a compliant member 190. Although the compliant member 190 is shown asa coiled spring, it is understood that the compliant member can compriseany compressible, resilient component which can fit between the latchbody 186 and the disk drive 14, and can be compressed therebetween tothereby exert a biasing force on the latch body 186. The latch 180 canbe held in a “locked” position (as shown in the figure) by catch 188,which is securely affixed to the chassis upper member 22.

In operation, as the latch is pivoted about the hinge 182 at its firstend using the handle 184, the latch moves from an “unlocked” position(not shown) and towards the disk drive 14. At a certain point during thepivoting of the latch body, the inner surface of the latch body 186, thecompliant member 190, and the front face of the disk drive 14 all comeinto serial contact, at which point force exerted on the latch handle184 to move it towards the disk drive is transmitted to the disk driveby the compliant member 190. This force urges the disk drive towards theelectrical plane (not visible in this view), and consequently theelectrical connectors on the disk drive and the electrical plane areurged together to electrically mate. At the end of its travel the latchhandle 184 is secured in a “locked” position by catch 188 as shown, andmovement of the latch handle ceases. In this “locked” position the diskdrive can move “outward” (with respect to the figure) against thecompliant member 190 to thereby relieve any excess stress which may beapplied to the electrical connectors. However, the latch body 186, assecured by the catch 188, prevents the disk drive from moving outward sofar that the electrical connectors become unmated. In this manner asufficient force can be applied to the disk drive to seat the electricalconnectors, while avoiding overstressing of these components.

A seventh embodiment of an apparatus in accordance with the presentinvention is shown in FIG. 15A. FIG. 15A depicts a plan view of a diskdrive 14 having an electrical connector 7 which is mated to a secondelectrical connector 1. Electrical connector 1 is mounted to anelectrical board or plane 25. Chassis members 23 and 15 aid insupporting the disk drive and the board 25. Unlike the previousembodiments of the invention described above, the apparatus shown inFIG. 15A does not comprise a traditional “latch”. However, it is properto consider the apparatus shown in FIG. 15A as comprising a latch, aswill be more fully described below.

The apparatus shown in FIG. 15A comprises a “latch” 210 which isanchored at a first end 212 to chassis side member 23, and at a secondend 216 to chassis side member 15. Preferably, the “latch” 210 isremovably attached to the chassis at one or both of ends 212 and 216.For example, “latch” end 212 can comprise a hook device, as shown, whichcan be engaged in anchor 214, which defines a hole for receiving thehook. The “latch” can be pivotally anchored to the chassis at the secondend 216, thereby providing the “latch” with an end 216 which engages thechassis. When the “latch” 210 is positioned as shown, it passes over thefront or face of the disk drive 14. The “latch” comprises a compliantmember 213, which is secured between the first end 212 and the secondend 216 of the “latch”. The compliant member 213 is configured to belongitudinally deformed in a resilient manner in response to a forcebeing applied to the first end 212 and the second end 216 of the“latch”. The compliant member 213 can be an elastomeric cord (similar toa Bungee® cord), or a plastic strap or the like.

In order to secure the ends 212 and 216 of the “latch” 210 to thechassis across the face of the disk drive 14, the compliant member 213is configured to be elongated by a predetermined amount to allow ends212 and 216 to engage anchors on the chassis. This elongation produceslongitudinal force within the complaint member. However, as a result ofthe face of the disk drive 14 protruding beyond the anchor points 212and 216 of the “latch” 210, a biasing force is produced. With referenceto FIG. 15B, a detail of the upper right corner of the disk drive 14 ofFIG. 15A is depicted, showing how the complaint member 213 is stretchedover the corner of the disk drive. As a result of elongation within thecompliant member, a longitudinal force F_(CM) develops. This force istransmitted to the anchor point at first end 216, and exerts force F_(A)on the anchor point. However, as can be seen, force F_(A) is not inalignment with force F_(CM), and therefore a vertical force componentdevelops. This is illustrated in the force balance diagram of FIG. 15C.As seen, force F_(A) is resolved into a horizontal component F_(AH), anda vertical component F_(AV). Force vector F_(AH) is balanced by theequal and opposite force F_(CM). However, to achieve a static solution,force component F_(AV) must also be met by an equal and opposite force.This equal and opposite force is found as the force F_(DD), which is theforce exerted on the disk drive 14 by the compliant member 213. Thisforce, F_(DD), is the force which holds the disk drive electricalconnector 7 into contact with the plane connector 1. However, due to thecomplaint nature of the compliant member 213, the compliant memberreduces the risk that an excessive force will be applied to the diskdrive and electrical connectors.

The Methods

The invention further includes methods for securing an electronic moduleinto a first electrical connector supported by an electrical board,which is supported by a chassis. The electronic module has a secondelectrical connector configured to mate in an electrically conductivemanner with the first electrical connector. As described above, aprimary problem with the prior art is that the force used to seat thedisk drive connector to the board connector is typically maintained evenafter the components have been mated. It is therefore desirable toreduce the force on the connectors after they have been mated.Accordingly, a first embodiment of a method in accordance with thepresent invention includes the step of applying a first force to theelectronic module to urge the electronic module towards the board from afirst position to a second position. This causes the electricalconnector mounted to the module to mate in an electrically conductivemanner with the electrical connector mounted to the board. After themodule connector is seated with the electrical board connector, a secondforce is applied to the electronic module to maintain the electronicmodule in the second, mated position. The second force is selected to benot greater than a predetermined force which will cause damage to themodule connector, the board connector, or the board itself. Preferably,the second force is selected to be less than the first seating force.

The second force which is applied to the module after it has been seatedagainst the board can be obtained by applying a biasing force againstthe device used to apply the first, seating force. For example, if alatch such as latch 20 of FIG. 5 is used to apply the first or “seating”force, then by applying a biasing force against the module or the latch,the force exerted by the latch on the module connector can be reduced.The biasing force can be applied by any of the apparatus described abovein FIGS. 6 through 13. Alternately, the second force which is used tohold the disk drive in place can be a resistive force provided by acompliant member configured to exert a known, limited force to the diskdrive. Such an apparatus is shown in FIGS. 14 and 15A. The method canalso include providing a catch to secure the module in place against thebiasing force or the resistive force.

While the above invention has been described in language more or lessspecific as to structural and methodical features, it is to beunderstood, however, that the invention is not limited to the specificfeatures shown and described, since the means herein disclosed comprisepreferred forms of putting the invention into effect. The invention is,therefore, claimed in any of its forms or modifications within theproper scope of the appended claims appropriately interpreted inaccordance with the doctrine of equivalents.

What is claimed is:
 1. An apparatus for securing a first electricalconnector mounted to an electronic module to a second electricalconnector supported by a electrical board, such that the first andsecond electrical connectors mate in an electrically conductive manner,and wherein the electrical board is supported by a chassis, comprising:a latch having a first end configured to engage the chassis and leverportion configured to exert a force on the electronic module when in afirst position to thereby allow the second electrical connector to beurged into the first electrical connector; a complaint member configuredto apply a sustained connector mating force to the electronic module, tobias the lever portion away from the first position, and to deform andthus relieve force on the electrical connectors; and a catch configuredto secure the latch in the first position.
 2. An apparatus for securinga first electrical connector mounted to an electronic module to a secondelectrical connector supported by a support structure, such that thefirst and second electrical connectors mate in an electricallyconductive manner, comprising: a latch having a first end configured toengage the support structure and a lever portion configured to exert aforce on the electronic module when in a first position to thereby allowthe first electrical connector and the second electrical connector to beurged together; a compliant member configured to bias the lever portionaway from the first position; a catch configured to secure the latch inthe first position; and wherein the compliant member comprises a segmentof the lever portion of the latch.
 3. The apparatus of claim 2, andwherein the segment of the lever portion of the latch is fabricated froma resilient material configured to orient the lever portion in a normalposition when the lever portion of the latch is unstressed, and when thelever portion is moved from the normal position to the first position,the segment of the lever portion is stressed to bias the lever portionaway from the first position towards the normal position.
 4. Theapparatus of claim 3, and wherein the segment of the lever portion ofthe latch is provided with kerfs to allow the segment of the lever toflex between the normal position and the first position.
 5. Theapparatus of claim 3, and wherein the segment of the lever portion ofthe latch is configured to exert a predetermined force in response to apreselected displacement of the segment from the normal position to thefirst position.
 6. An apparatus for securing a first electricalconnector mounted to an electronic module to a second electricalconnector supported by a support structure, such that the first andsecond electrical connectors mate in an electrically conductive manner,comprising: a latch comprising a compliant segment configured to bedeformed from a first normal position to a second stressed position, thelatch having a first portion configured to exert a force on the supportstructure, and a second portion configured to exert a force on theelectronic module away from the first electrical connector when thelatch is in the stressed position.
 7. The apparatus of claim 6, andfurther comprising a catch configured to secure the compliant member inthe stressed position.
 8. An apparatus for securing a first electricalconnector mounted to an electronic module to a second electricalconnector supported by a support structure, such that the first andsecond electrical connectors mate in an electrically conductive manner,comprising: a compliant member configured to be deformed from a firstnormal position to a second stressed position, the compliant memberhaving a first portion configured to exert a force on the supportstructure, and a second portion configured to exert a force on theelectronic module away from the first electrical connector when thecompliant member is in the stressed position; and wherein the compliantmember is a flexible portion of a handle of a latch, the latch having afirst end configured to engage the support structure, the latch beingpivotally mounted to the electronic module at a point between the firstend of the latch and the latch handle.
 9. An apparatus for securing afirst electrical connector supported on an electronic module to a secondelectrical connector, comprising a compliant member configured to applya sustained connector mating force to the electronic module.
 10. Theapparatus of claim 9, and wherein the compliant member is configuredsuch that the sustained connector mating force is a force which will notcause damage to the first electrical connector or the second electricalconnector.
 11. The apparatus of claim 9, and further comprising asecuring member configured to urge the first electrical connector andthe second electrical connector together in an electrically matedmanner.